Process and apparatus for the production of low boiling point hydrocarbons



Patented May 22, 1923.

UNITED sTATEs PATENT oEFicE. l

JOHN c. BLACK, or nEsrREHaN, LOUISIANA. v

PROCESS AND APPARATUS FOB, THE PRODUCTION F LOYVA BOILING- POINT HYDRO- CARBONS.

Application led June 20, 1922. Serial No. 569,757.

To all whom it may concern.'

Be it known that I, JOHN C. BLACK, a citizen of the United States, residing at Destrehan, St. vCharles Parish, Louisiana, `have invented certain new and useful Improvements in a Brocess and Apparatus for the Production of Low Boiling Point Hydrocarbons, of which the following is a specification.

This invention relates to the manufacture of low boiling point hydrocarbons from hydrocarbons and to a process and apparatus especially useful in increasing the production of socalled gasoline from relatively heavy hydrocarbons having high boiling points.

In my co-pending applications 344406 of December 12, 1919, and 492,377, of August 15, 1921, of which is a continuation in part, I describe a method and apparatus for the production of low boiling point hydrocarbons from high boiling point hydrocarbons. My present invention is an improvement thereon and I am enabled to obtain an increased ield of the lower boiling point hydrocarbons from those "of higher boiling point. This result is obtained bythe arrangement of the heating furnace, and coils and the heat control of the coils. There is also an economy in labor of operation and equipment 4over that required heretofore, and a larve. increase of capacity, all of which ma es the invention useful and valuable to the art to which it relates.

To' successfully operate the process it is' essential to emplo va pressure high enough to prevent lvaporization of the hydrocarbons while undergoing decomposition or cracking and it is also essential to maintain the pressure on the carbon precipitating chamber for if the hydrocarbons are permitted to vaporize, rial is deposited at a rapid rate and would cracking is 1n a condition easily removable due to its deposition from a liquid Ysuspension and is not in the form usually found of higher boiling point'- thev present applicationcarbonaceous matecause foulin of the tubes, carbon precipiin other processes but is more in the nature of an oily ranular deposit easily disintegranted an purged from the apparatus. That is to say I maintain pressure from the pump throughout the system to the pressure regulating and discharge valve and by so doing I minimize the carbonaceous deposits and obtain them in an easily removable form. I have also found that cracking in the liquid phase produces low boiling point hydrocarbons of superior quality to those processes operating with the mixed liquid vapor phase or the vapor phase by producing less of the unsaturated hydrocarbons. It also producesl lproducts of better odor and color and better boiling points and produces finished gasoline approaching more nearly the quallty of natural gasoline produced from crude etroleum than those processes not using high pressure. For this reason and for those previously mentioned I maintain the hydrocarbons underv the hydrocarbons usuallyl employed for cracking in a liquid condition,

although in Vsome instances I have used higher pressure, and in others a lower pressure, dependin on the oil under treatment.

I do not wis to limit myselr` to the pressure stated above as the process can be operated on pressures lower than 7 0 atmospheres with good results and also at a higher pressure if desired, but from a practical standpoint I prefer to operate at approximately. i

0 atmos heres at the terminal gauges and valves. he ingoing pressure is usually 200 pounds to 300 pounds in excess of the terminal pressure, and when' this differential increases to any extent overthat shown at normal operating condition it is an indicaf tion that the system is becoming fouled and' should be purged of theaccumulated carbonaceous VI natel'ifl. The temperaturel relos4 quired for the particular hydrocarbons being treated may be determined by the increase of Baum gravity of a sample after treatment, supplemented usuallr by a distillation test to determine the yield of hydrocarbons boiling between certain speciic temperature limits. In practice I have found that for some grades of oil the best temperature of reaction ranges from 7 50o F. to 850 F., while for others usually of higher Baum gravity the temperature range may be asv high as 900 F. and in some cases as high as 1000 F.

In a cracking reaction the higher the temperature with a suilicient supply of heat to iprevent diminution of sensible heat and sufcient time to permit of complete reaction at that temperature, the larger will be the yield of low boiling point'hydrocarbons, and the greater will be the production of carbonaceous material at any given pressure, so that in a practical `commercial plant, it is necessary for the operator to choose the most eliicient temperature and pressure and duration 0f such temperature and pressure so that as long a run as possible may be made without the necessity of cleaning out the carbonaceous accumulations consistent with a sufficient yield of low boiling point hydrocarbons to make the operation of the plant most profitable.

To perform my process I have provided a suitable apparatus, although it is understood that, the process may be performed by other apparatus of different arrangement, but embodying the same fundamental principles.

For convenience in describing the process the, apparatus which I prefer to employ is illustrated in the accompanying drawings in which Figure 1 is a part sectional part elevational View of the apparatus.

Fig. 2 is a front elevation of the furnace showing the preferred arrangement of the furnace, and,l

Fig. 3 is a pressure temperature curvel showing in a diagrammatic way the change in pressure with increase of temperature of a hydrocarbon oil undergoing a cracking reaction in a vapor tension measuring apparatus. It-i's an object of the invention to provide means for detecting any irregular action in the cracking coils or other part of the apparatus, the irregular action being usually caused by. carbonaceous deposits therein.

One of the objects offmyl present invention is to heat the hydrocarbons to an increasing temperature in their progress through the tubular coils and to furnish th greater ortion of the latent heat of reac-v tion in t e nal coils of. my apparatus where I have positive control of the. temperature to the end that I may maintain thelii?.l y@

uniform temperature. or even a rising temperature and also to supply heat over .a longer period of time at the temperature which I elect to operate at and to permit the hydrocarbons to absorb the latent heat of reaction without diminution of sensible heat thereby bringing about the maximum cracking effect obtainable at that temperature. I have noted that when a hydrocarbon has reached a certain cracking temperature and no further heat is supplied beyond the heat ordinarily required to I maintain that temperature that a diminution of temperature takes place due to the abstraction of heatfrom the body of the hydrocarbons and rendered latentby the endothermic reaction taking place and that the diminution of temperature reduces the rate of react-ion and total production of low boiling hydrocarbons, whereas when the latent 'heat is supplied from an. outside source an increased yield results.l

I disclose two forms for the subsequent disposition and manipulation of the cracked hydrocarbons but it is to be understood that other means may be employed to process the cracked hydrocarbons after they leave the cracking zone. I may separate or fractionate the hydrocarbons by methods shown in my before mentioned applications, all of of which are important to the proper opera'- tion of the completeprocess, and my present drawings and specification disclose a method `in detail to show more clearly the separation of the desired low boiling point hydrocarbons so that one skilled in the art of oil refining-would be enabled to construct and operate the apparatus from the description herewith given.

In the drawings' 1 represents a furnace having therein horizontal partitions 2, 3, 4

and 5, with openings 2', 3', 4', and 5', in the partitions, and openings 6 and 6 in the furnace walls, these openings 6 and 6 having covers 7 and 7' that can be readily removed for the purpose of getting at the coils 9, 9', 10 and 10 within lthe furnace. Heat may be supplied to the coils inthe furnace by ordinary burner tubes 6 which may be supplied in the usual manner with oil and steam through suitable tubes having valves 6' and' 6. By means of these valves the heat supplied to each coil may be regulated as desired..

The coils are constructed as shown in my prior applications with the exception that they are arranged in a double series of continuous coils as shown in Fig. 2. The hydrocarbons to be cracked may be pumped by a pump 18 through the tube 31, heat exchanger 22, tube 8 and coil 8 into the series of coils 9 and 9 thence through them and downwardly through atubular connection 12 to the series of coils 10 and. 10'.

Under son@ Condit-ions I may wish te pass the oil around the heat exchanger 22. In order to do this I insert a valve 31 in the tube 31 .and-valve 8" in tube 8 and connect a branch pipe 29 t0 the pipes 31 and 8 and insert a valve 29 in this branch pipe. Then by closing valves 31 and 8 and opening valve 29 the oil will pass through the branch pipe 29 directly into pipe 8 without passing through the heat exchanger 22.

For convenience I insert a pyrometer 14 in the connection between the coils 9 and 10, another pyrometer 15 between the series of coils 10 and 10', and a third pyrometer 16 at the outlet of the iinal coil 10.

From the coils the pressure developed by the pump 18 forces the hydrocarbons into what I denominate a carbon precipitating chamber. This chamber is of considerably larger cross sectional area than the cross sectional area of the tubes and is intended to perform any or all of the following functions,

the fundamental function being to reducey the rate of flow of the hydrocarbons after they have passed through the heating coils to facilitate the deposition of carbonaceous material produced in the cracking reaction and to deposit them in such a condition and in such a receptacle as to be easily removable from the apparatus. Another function of the carbon precipitating chamber is to4 allow the hydrocarbons therein while at a high temperature to undergo further dissociation or polymerization if the cracking reaction has not been complete in the heating coil which may be caused by ineicient operation or other causes.

To facilitate the removal of the carbonaceous material the carbon precipitating chamber may have detachable heads 20 which may be conveniently removed and the carbon precipitating chamber purged of the carbonaceous deposits whenthe ordinary methods of purging hereinafter described are not effective.

To purge the apparatus of carbonaceous material in the ordinary method of purging, the valve v8O in pipe 80 is closed and the valve 86 in pipe 86 is opened whereby the oil supply to the pump 18 is shut oif and a supply of water substituted for the oil,

the pump is continued in operation displacing the oil in the system with water and when water appears at the purge connection 25 and v alve 25 on the trap 23, then the coils andcarbon precipitating chamber are sufficiently cleared of oil toA permit the water and steamto be discharged from4 the purge connection through -valve` 85 on the bottom of the carbon'precipitating chamber and the carbonaceous material is discharged with the water and steam. This is continued until the apparatus is cleared ofdeposits, the valve 86 is then closed and valve 80 opened and a supply vof oil pumped through the appatower. The fires-aresmaintained under the heating coils during the purging operation -to produce highly heated water or steam which acts as the purging agent.

There is a connecting tube 21 between the carbon precipitating chamber and the heat exchanger 22, this latter ma confveniently' be similar to the heat exc anger shown in my prior applications, the connection 21 passing throu h the heat exchanger and into an oil y-pass trap 23, which may comprise a tube or receptacle as shown, having therein a baffle 24, and a gauge 23 to show the pressure of oil in the trap 23, the trap 23 is preferably placed in a cooling tank 95.

The hydrocarbons when projected against the baille 24 must pass around the same and the baffle will therefore act as a delector to facilitate thfprecipit'ation of suspended matters not previously precipitated and such matter may be purged from the system through a tube 25 and valve 25.

Leading from the trap 23 is a connection 26 connected to the'trap a considerable distance from the bottom thereof and this connection leads through a cooler 26 to what I denominate a control board which constitutes a convenient means for supporting in proximity to each other the control valves 27 and 28 and gauges 30 and 30. The connection 26 and valve 27 leads into what I denominate a slop tank for receiving uncracked oil and, or, water.

Under certain operating conditions. Ir may wish to switch the oil vsupply going to the coils into the slop tank. In order to do this I insert a connecting pipe 32 having a valve 32 therein between pipes 31 and 26. Then by opening valve 32 the oil may be passed from pump 18 or disf chargedA back from pipe 8y through pipes.

31, 32, and 26 and valve 27 to the 'slop tank.

By arranging the valves 27 and 28 andv in the system by regulation of the valve- 27 or valve 36 as the case may be, or if he observes lthat there is an abnormal differential between lthe gauges 30 and 30' hooded opening' 50 and have been partiallyy he knows that the coils or carbon catcher or both are becoming fouled with carbonaceous material and should be purged.

The trap 23 is connected with a tower which is denominated on the drawing a fractionating tower by a tube 36 having a pressure regulatingand discharge valve 36 therein, which permits the hydrocarbons to be delivered to the fractionating tower. The by-pass trap 23 has several functions as follows: When discharging into the fractionating tower through line -36 and pressure-reducing and discharge valve 36', trap 23 acts as a' catcher for suspended particles of carbon and as a pressure transmitting device in conjunction with the line 26, and cooler 26 leading to the gauge 30 on the control boa'rd, valve 27 being closed when so operating.

This by-pass and connections as shown, gives the attendant an easy means of inspection land comparison of the inlet and outlet gauges 30 and 30. Or if, for any reason, it is not desired to discharge the hydrocarbons, or during purging, the water or steam into the fractionating tower, then valve 36' is closed and the main stream of hydrocabons or water when purging, is bypassed through line 26 through the cooler 26 and discharged through the pressure regulating and discharge valve 27 into the slo tank o'r the cracked oil tank as may be deslred. In this manner two methods of operation may be employed each independent of the other or it may be found desirable to fractionate a portion of the hydrocarbons and cool and store the balance, this ma be readily carried out by the apparatus as described. The fractionating tower comprises a series of compartments 41, 42 and 43. The compartment 41 has a conical bottom for collecting the deposited residues and passing them through a tube 46 having a. valve 46 therein, to what I call a residue tank.

The compartment 41 has arranged in it just above the point where the tube 36 enters the compartment 41, a tile structure 41 made up of staggered tiles to batile the upward assage of the hydrocarbon vapors througii the tile structure and to catch the particles of oil entrained in'the vapors-to allow them to drop back onto the' conical floor at the bottom of the compartment 41.

The vapo'rs pass on up through the. compartment 41 and through a hooded opening 50 and thence through a tile structure similar to the tile structure 41 immediately above the hooded opening. This tile structure in turn acts as a washing means for the vapors that have passed through the condensed and absorbed on the tile surfaces due to the wetted surfaces of the tiles and to the temperature maintained in the seci of hydrocarbon made u tion 42 by thel injection therein of oil through a sprinkler head 51" connected with a pump 57 by a tube 51 having a valve 51 therein. A tube 58 having a valve 58 and a trap 58 therein opening into the compartment 42 near its bottom conducts the condensate in 42 together with the vwash oil to the supply tank.

In the fractionating tower above the compartment 42 may be arranged a compartment 43 having a tile structure similar in its construction and functions to that of compartment 42 but maintained ata lower temperature in o'rder to condense out the lower boiling hydrocarbon fractions, the sprinkler head 52 in this compartment 43 being connected to a pump 59 by a tube 52 having therein a valve 52 and the pum 59 in turn being connected to a tank whic may be conveniently denominated a heavy na ihtha tank.`

` fonnected to the lower portion of compartment 43 is a line 64 having a valve 64 and trap 64 and connected to the heavy naphtha tank.

Of cou'rse there may be other similar compartments in this fractionating tower if additional cuts or fractions are desired.

Connected to the top of the fractionating tower is a pipe 63 containing therein a valve 63 leading through. a condenser and thence through a Ylook box 66 and tube 65 to what may be conveniently denominated a light naphtha tank. This ipe 63 takes from the upper part of the fractionating tower the uncondensed hydrocarbons not separated out in the lower compartments. The valves 46', 58', 63 and 64 are provided to permit the tower to operate under pressure if desired. The condensate from. the vapors issuing from the upper compartment 43 are usually denominated light naphtha, the mixed condensate and wash oil from the lower part of the compartment 43 heavy naphtha and from .the compartment 42 is taken a grade of condensate and wash oil the latter being taken from the supply tank and which is returned to the supply tank together with the condensate and from the supply tank it is passedv through the furnace coils to be treated.

A cooler 60 may surround the pipes 58 and 64 leading from near the bottom of the compartments 42 and 43 for cooling the condensate and the wash oils from the injection heads 52 and 51 before discharging them respectively into the heavy naphtha tank and the supply tank.

I provide a pipe 80 havinga valve 80' said pipe extending from the supply tank to the pump 18 with a branch pipe v81 having a valve 81 therein connecting it to the slop tank and another branch pipe 86 havingv a valve 86 to a water supply tank,

l prevent vaporization of the lower Y the cracked oil tank The oil supply tank takes its supply from the compartment 42 through ipe 58 and from an outside source of supp y (not shown) through a pipe 87.

A cracked oil tank is rovided connected with pipe 26 and valve 2 The operation of my apparatus is apparent from the foregoing, but to briefly summarize it, the oil to be cracked is pumped by pump 18 from the supply tank through "pipe 80, thence through ipe 31 and heat exchanger 22 or through y-pass 29 to pipe 8 to the coil 8 thence through the series of coils 9 and 9 and 10- and 10 in the furnace, thence to thel carbon precipitating chamber, thence through the heat exchangerto. the by-pass trap 23, from the trap 23 there two flow lines, one through pipe 36 and pressure regulating valve 36 to the fractionating tower, and one through pipe 26, cooler 26 and to the control board -and valve 27, and discharging to the cracked oil tank. through line 26 and valve 27" or into the slop tank through valve 27.

It is to be understood that the capacity of the heat exchanger 22 may be such as to cool the hydrocarbons to a degree Sullicient to permit only the low boiling fractions to vaporize in the fractionating tower upon release or partial release of pressure,

by the pressure regulating valve 36.

It is also understood that the capacity of the cooler 26 is such as to cool the hydrocarbons discharging to the slop tank or to the cracked oil tank to a degree to oiling point hydrocarbons desired when the pressure is released and they are discharged into said tanks. lIn this connection it must be understood that there are gases present due to the decomposition of the hydrocarbons that are not condensed at atmospheric temperatures and pressure and are generally lmown as permanent gases.

In Fig. 1 of the drawings 9() and 91 show the permanent gas vents connected to gas vents connected to the vapor condenser connected to the fractionating tower.

The permanent gases discharged into the vents are preferably conducted to gasabsorbers (not shown) to absorb out any low boiling hydrocarbons that might be entrained in the gas, and thev residual gases are then used as fuel under the furnaces or elsewhere if so desired.

By referring to Fig. 3 it will be observed I that as heat is applied to the hydrocarbons that there is a rapid rise of temperature with onl a small rise in pressure as shown by the a ost vertical line of the curve and that when the temperature reaches the cracking oint, the vapor tension or pressure rapi y increases with a relatively small and 92 and 93 the increase of temperature although heat is continued to be applied at the same rate, thus indicating that the heat being applied to the oil is rendered latent by the endothermic reaction of cracking.

In my new process I so construct my apparatus that I take advantage of the phenomenon above described wherein I am enabled to furnish the latent heat of the endothermic reaction at a time when the reaction is most active and the absorption of heat is at a maximum. Furthermore, I an enabled to maintain the temperature or even to increase the. temperature if I so desire during the maximum cracking eriod, therethe drawings that I have provided separate coils and separate means 6" for supplying heat to each of the-coils 9, 9', 10 and 10 and have provided suitablepyrometers for ob` servation by the attendant whereby he may be governed in controlling and regulating the heat supplied to the coils.

By this arrangement of coilsand heat .control means the temperature of the hydrocarbonsmay be so regulated as to bring coil 10 to the maximum temperature to be employed for the particular hydrocarbons under treatment, then suppl ing suflicient heat to coil 10 to maintain t e maximum temperature of operation and to supply the hea.-4 required in the endothermic reaction an by this arran ement and mode of operation, I have foun that I obtain an mcreased yield of low boiling point hydrocarbons.

In the operation -of my process I keep the hydrocarbons under sullicient pressure to maintain them in the liquid phase during cracking, carbon precipitation and to the point of discharge for subsequent treatment.

The hydrocarbons are passed tothelcarbon precipitating chamber, wherein their rate of flow is reduced to permit 'of the separation 4of the carbonaceous material produced in the Vcrackin reaction, which will be deposited from agliquid suspensionand will be in a condition easily removed and also if the reaction is incomplete in the coils, the reac' tion will continue in a minor degree in the carbon precipitating chamber.

I claim as my invention:

1. In an apparatus for 4convertin high boiling point hydrocarbons into low boiling point h drocarbons, a hydrocarbon source of supp a furnace having a plurality of compartments, a plurality of series of coils in the upper part of the furnace, one series in each compartment, a plurality of series of d lill l lo coils in the lowerpart of the furnace one the upper compartment of the furnace to a series in the lower compartments, a connection between the series in the lower part of the furnace, means for applying heat to each series of coils, means for regulating the supply of heat as desired for each coil, a heat indicator between the upper series and the lower series of coils, a heat indicator between the plurality of series in the'lower part of the furnace and a heat indicator on the outlet of the series of coils whereby regulated amounts of heat may be supplied as desired.

2. In an apparatus for converting high boiling point hydrocarbons into low boiling point hydrocarbons, a hydrocarbon source of supply, a furnace having a plurality of compartments, a plurality of series of coils in the upper compartments of the furnace, one series in each compartment, a plurality of series of coils in the lower compartments of the furnace one series ineach compartment, a connection between the series in the upper part of the furnace, a connection from one of the series in the upper part of the furnace to a series in the lower part, a

connection between the series in the lower part of the furnace, means for supplying heat to each series of coils, means for regulating the supply of heat as desired for each coil, a heat indicator between the upper series and the lower series of coils, a heat indicator between the plurality of series in the lower part of the furnace, a heat indicator on the outlet of the series of coils whereby regulated amounts of heat may be sup lied as desired,.and a carbon precipitating c amber outside the furnace with a conduit between the inal series of coils and the carbon preci itating chamber.

3. n an apparatus for convertin high boiling point h drocarbons into low oiling point h drocarbons, a hydrocarbon source of supp y, a furnace having a plurality of compartments, a plurality of series of coils in the upper compartments of the furnace, one series in each compartment, a plurality of series of coils in the lower compartments of 'the furnace one series in each compartment,

a connection between the series in the upper part of the furnace, a connection from one of the series in the upper part of the furnace to a series in the lower part, a connection between the series in the lower part of the furnace, means for supplyino' heat to each series of coils, means for reguIating the supply of heat as desired for each coil, a heat indicator between the upper series and the lower series of coils, a heat indicator between the plurality of series inthe lower part of the furnace,`a heat indicator on the outlet of the series of coils whereby regulated amounts of heat may be supplied as desired, and a carbon precipitating chamber outside the furnace with a conduit between the final series of coils and the carbon precipitating chamber, said carbon precipitating chamber having detachable heads and an outlet for the hydrocarbons.

4. In an apparatus for converting high boilin" point hydrocarbons to low boiling point thydrocarbons comprising a source of supply, a pipe line connected thereto, a valve in the pipe line, a gan e also in the pipe line, a furnace, coils in t e furnace connected to the pipe line for heating the hydrocarbons, a carbon precipitating chamber connected to the coils, a pipe line outlet for the carbon precipitating chamber, and an oil by-pass trap in said outlet pipe line, said by-pass trap being connected at its upper end to an outlet pipe line having therein a discharge valve for the heated hydrocarbon, the lower part of the trap having an outlet pipe line leading therefrom to a dischar e tank, the pipe line leading from the su pIy tank to the coils and the pipe line lea 1n from the by-pass trap to the discharge tan being arranged in proximity to each other at one point, and gauges connected with the pipe lines near this point whereby an attendant by observation of the gauges may operate said valves to regulate the pressure in the coils and the carbon precipitating chamber..

5. In anapparatus for converting high boilin point hydrocarbons to low boiling point iydrocarbons comprising a source of supply, a pump and connections thereto, heating coils and a connection between the pump and heating coils, a pressure -gauge and. valve in said connections, an outlet for the coils, an oil byass trap connected to said outlet, a blow-o discharge at the lower end thereof, an upper connection to a pressure reducing and discharge valve, a lower connection to a discharge pipe line, a pressure auge and valve therein in proximity to ne first mentioned pressure gauge and valve whereby an attendant may, by observation of the gauges so regulate the valves as to maintain the desired pressure in the coils, trap and connections as described.

6. In an apparatus for treating hydrocarbons comprising a source of supply, a control board, a furnace having a series of coils therein, a connection between the source of supply and the coils, a gauge and valve in said connections attached to said control board, an outlet for the coils, an oil by-pass trap in the outlet, and connections from the trap to a discharge, said connections leafling from a point above the bottom of the trap and having therein a gauge and valve attached to the control board for the purpose described.

7. In an apparatus for treating oil, the

combination of a furnace including coils,

conduit connected to the upper portion of the trap having therein a pressure reducing valve whereb the hydrocarbons may be passed throug the upper part of the trap, an outlet conduit intermediate the u per and lower portions of said trap, a codling means for the trap, andI a purging outlet from the bottom of the trap, as described.

8. In an apparatus for treating oils, the combination of a source of supply, heating coils, a carbon precipitating chamber and an oil by-pass trap, connections between the coils and carbon precipitating chamber and trap, a fractionating tower, connections between the trap and said fractionating tower,

a reducing valve in said connections and means for spraying oil into the tower to meet the oil vapors after they have been discharged into the tower from the reducing valve.

9. In an apparatus for treating oils, the combination of a' source of supply, a heating coil, a carbon precipitating chamber connected to the heating coil, an oil by-pass trap connected to the carbon precipitating chamber, av reducing valve connected to the trap and a fractionating tower with connections between the reducing valve and the tower and means to supply washing oil in the tower to. meet the oil vapors as they ascend in the tower. l

10. In an apparatus for cracking and fractionating oil comprising a means including a furnace and coils for heating the oil and delivering it under pressure to a reducing valve, a fractionatin tower and connections from the reducing valve to the tower, said tower being divided into compartments, and means to su ply scrubbing oil in each compartment rom a supply without passing through said coils, openings between the compartments to allow the vapors delivered in the tower from said coils to rise and meet the scrubbing oil,

and connections for leading away from each com artment the condensed vapors and scru bing oil to separate storage tanks.

`11. In an apparatus for convertin high boiling hydrocarbons to low boiling ydrocarbons, thezcombination of-a furnace having coils therein anda carbon precipitating chamber in series relation with the coils with connections between the coils and chamber, separate valved oil and water outlets from said chamber, an oil supply and a water supply withvconnections from each supply to the coils and valves in said connections whereby said sources of supply may furnish oil to said coils and carbon precipitating chamber and when. desirable alternate to a supply of water to purge the coils and carbon precipitating chamber of accumulated carbonaceous material, the oil being discharged through a separate discharge from the water discharge.

lin w ereby the suppl Aprecipitating' chamber, and connections between them 'and between the pump and coils,

said chamber having a main discharge and a blow-off` discharge, said first mentioned connections having suitable valves whereby the pump may be shifted from oil to water and the oil or water forced through the coils and main discharge ofv the ,carbon precipitating chamber and water, steam and carbonaceousmaterial discharged therefrom throu h the blow-olf discharge. Y

13. n an a paratus for treating oil, 'a source of supp y, heating coils and connections between the supply and coils, an oil by-pass trap, a discharge tank and discharge connections from the coils to the trap and from the trap to the tank, said supply connections and discharge connections having a byass between them with a ,valve thereof oil may be switched from the supp y to the discharge connections without passing through the coils or trap.

14. In an4 apparatus for treating hydrocarbons, the combination of heating coils and a trap with connections between the same, said trap havin its lower partwater cooled, an outlet there rom for the discharge of Aprecipitants, and anz up er and intermediate outlet for the disc rge of hydrocarbon. v

15. A rocess which consists in cracking hydrocarbons under pressure and passing them while still under pressure to a fractionating tower, reducing the pressure and fractionating under this reduced pressure, the vapors of the hydrocarbons containing various ,oil fractions of different specific gravity and different boiling points by subjecting the vapors to a washing, cooling and condensing action of a liquid hydrocarbon oil, sepa-rating the'wash oil together with the admixed condensate from the vapor, then cooling the mixture of oils and returning a` portion to the washing compartment to again act as a washing, cooling and condensing medium to separate the fractions of the vapor similar in their specific gravity and boiling points to the first said condensate whereby the wash oil maintains substantially a uniform quality, then passing the remaining uncondensed vapors to an additional washing, cooling and condensin compartment wherein the vapors are su jected to 1a washing and condensing action with a wash oil of lower specific gravity and lower boiling point to separate hydrocarbonsfrom the vapors in a manner similar t0 that followed in the first washing compartment and separating from said vapors a condensate of lower specific gravity and lower boiling points than the separated condensate in the first described compartment, then passing the residual uncondensed vapors to a condenser Wherein the condensable vapors are liquefied, in this manner obtaining a plurality of condensates of uniform and predetermined quality.

16. The process of cracking hydrocarbons which consists in passing them through heating coils, arranged in series relation relative to each other, gradually heating the hydrocarbons by successive heating means to the maximum temperature selected for that particular oil and regulating the heating means so that said maximum temperature would be attained as the hydrocarbons enter the final coils, then passmg the oils through the final coils and while so passing them maintaining substantially the said maximum temperature by supplying the vhydrocarbons with sufficient heat from the p final heating means to at least equal the heat that is absorbed by the hydrocarbons in the rendothermic reaction of cracking and maintaining sufficient pressure upon the hydrocarbons to prevent the vaporization thereof, then reducing the pressure and vaporizing the lower boiling hydrocarbons, fractionally condensing them and returning the suitable fractions to be again subjected to treatment.

17. A process of cracking hydrocarbons which comprises forcing them through preliminary heating coils arranged 1n series relation relative to each other, where the flow of the hydrocarbons is reduced to per-.

mit of the separation of the carbonaceous material of reaction While the hydrocarbons are maintained under sufiicient pressure to maintain them in a liquid state whereby the carbonaceous material is deposited in a condition easily removed, then discharging them through a pressure regulating valve into a fractionating apparatus to separate the hydrocarbons of different boiling points.

18. A process of cracking hydrocarbons which comprises forcing them -throu h reliminary heating coils lwhere the y rocarbons are heated to substantially the maximum temperature to be employed in the cracking operation, then ,passing them through a final heating coil wherein the heat is supplied to the hydrocarbons that is rendered latent by the endothermic reaction of cracking and sufiicient heat is su plied to maintain the hydrocarbons at su stantially the said maximum temperature throughout the entire coil, thereby subjecting the hydrocarbons Dto a prolonged period of heating at said maximum temperature,

whereby substantially maximum conversion is obtained for the temperature emplo ed and time of reaction, then passing the hy rocarbons to a carbon precipitating chamber wherein the rate vof flow of the hydrocarbons is reduced to permit of the separation of the carbonaceous material of reaction while the hydrocarbons are kept under sufficient pressure to maintain them in a liquid state whereby the carbonaceous material is deposited in a condition easily removed, then passing them through a cooler to reduce their temperature to such a degree as to permit only the lower boiling point hydrocarbons to vaporize upon the release of the pressure,l then condensing the vaporized fractions.

19. A process of cracking hydrocarbons 'which comprises forcing them through preliminary heating coils where the hydrocarbons are heated to substantially the maximum temperature to be employed in the cracking operation, then passing them through a final heating coil wherein the heat is supplied to the hydrocarbons that is rendered latent by the endothermic reaction of cracking and suicient. heat is supplied to maintain the hydrocarbons at substantially the saidmaximum temperature throughout the entire coil, thereby subjecting the hydrocarbons to a prolonged period of heating at said maximum temperature, whereby substantially maximun conversion is obtained for the temperature em lo ed and time of reaction, then passing the y roca-rbons to a carbon precipitating' chamber wherein the rate of flow 'of the hydrocarbons is reduced to permit of the separation of the carbonaceous material of reaction while the hydrocarbons are 'kept under sufficient pressure to maintain them in a liquid state whereby the carbonaceous material is deposited in a condition easily removed, then partially reducing the pressure to permit the lower boiling point hydrocarbons to, vaporize, then fractionally condensing them to separate the hydrocarbons of different boiling points.

20.-A process of cracking hydrocarbons which comprises forcing them through preliminary heating coils where the hydrocarbons are heatedv tov substantially the maximum temperature to be employed in the cracking operation, then passing them through a final heating coil wherein the heat a carbon precipitating chamber wherein the rate ot' flow ot' the hydrocarbons is reduced to permit ot the separation of the carbonaceous material ot' reaction while the hydrocarbons are kept. under sutcient pressure to maintain them in a liquid state whereby the carbonaceous :material is deposited in a condition easily removed, then while theyV are under sufficient pressure to maintain them in a liquid condition cool them to such a degree that the low boiling hydrocarbons desired are not vaporized when the pressure is reduced to substantially that of the atmosphere and discharged from the apparatus.

21. The process of cracking hydrocarbons which consists inpassing them through heating coils arranged in series relation relative.

to each other, gradually heating the hydrocarbons to the maximum temperature selected tor that particular oil and regulating the heating so that said maximum temperature would be attained as the hydrocarbons enter the nal coils, then passing the oil through the final coils and while so passing it, maintaining substantially the said maximum temperature by supplying the hydrocarbons with sutlicient heat to at least equal the heat that is absorbed by the hydrocarbons in the endothermic reaction of cracking and maintaining sufficient pressure upon the hydrocarbons to prevent the vaporization thereof,A then reducing the pressure and discharging them into a fractionating tower wherein the lower boiling point hydrocarbons are Vaporized and where the vapors containing hydrocarbons of various boiling points may be fractionated by treating the vapors with a washing, cooling and condensing hydrocarbon wash oil, separating from the vapors a traction similar in .physical properties to the wash oil, then subjecting the remaining vapors to a subsequent. similar treatment whereby a fraction may be separated corresponding in physical characteristics to the wash oil employed, and then condensing the residual vapors, thereby obtaining a plurality otl fractions that may be separately recovered.

22. A process ot' cracking hydrocarbons which comprises Jforcing them through preliminary heating coils where the hydrocarbons are heated to substantially the maximum temperature to be employed in the cracking operation, then passing them through a final heating coil wherein the heat is supplied to the hvdrocarbons that isrendered latent by the endothermic"'ireaction of cracking and suliicient heat is supplied to maintain the hydrocarbons at substantially the 'said maximum temperature throughout the entire coil, thereby subjecting the hydrol carbone to `a prolonged period of heating at said maximum temperature, whereby substantially maximum conversion is obtained for the temperatureemployed and time of reaction, then passing the hydrocarbons to "a carbon precipitating chamber wherein the rate of iow ot the hydrocarbons is reduced -to permit of the separation of the carbonaceous material ofreaction while the hydrocarbons are kept under sutiicient pressure to maintain them in a'liquid state whereby the carbonaceous material is deposited in a condition easily removed, then reducing the pressure and discharging them into a fractionating tower wherein the lower boiling point hydrocarbons are vaporized and where the vapors containing hydrocarbons of various boiling points may be fractionated by treating the vapors with a washing, cooling and condensing hydrocarbon wash oil, separating from the vapors a fraction similar in physical properties to the wash oil, then subjecting the remaining vapors to a subsequent similar treatment whereby a fraction may be separated corresponding in physical characteristics to the wash oil employed, and then condensing the residual vapors, thereby obtaining a plurality of fractions that may be separately recovered.

, 23. A process of cracking hydrocarbons comprising heating them in continuous tubular heating coils to a temperature sulfilcient to crack them, heating the coils pro- .ing them into a carbon precipitating chamber of larger cross sectional area than the cross sectional area of the coil wherein the rate of flow of the liquid hydrocarbons is retarded, permitting the precipitation of the carbonaceous material from a liquid suspension and prolonging the time of reaction, whereby further decomposition digestion and polymerization of the hydrocarbons will result, and maintaining ,the hydrocarbons in the heating coils, and car-v bon precipitating chamber under sufficient pressure to maintain the'm in substantially a liquid condition and maintaining said pressure to the point of pressure reduction and discharge.

24. The continuous process of cracking hydrocarbons and periodically removing carbonaceous deposits which consists in simul'taneously passing the hydrocarbons through and heating them in cracking coils arranged in series relative to each other to a temperature sufficient to crack the hydrocarbons and maintaining them While thus treated under sufcient pressure 'to prevent their vaporization during the cracking and carbonaceous deposition period, whereby the carbonaceous depositsv are in a condition easily removed, then displacingr the hydrocarbons in the apparatus with water by passing the Water lthrough the apparatus in the same direction of ow as the hydrocarbons, then discharging the water andgenerated steam together with the residual carbonaccous materials of reaction from the apparatus Wherebythe various elements of the apparatus are cleared of carbonaceous deposits, then displacing the water in the apparatus with hydrocarbons and again subjecting the hydrocarbons to the cracking reaction in a cycle of operations, substantially as described.

25. The process of cracking hydrocarbons and removing carbonaceou-s deposits which consists in causing the hydrocarbons to pass ciently cracked and the carbonaceous de` posits are left in a condition easily removable, then displacing the-hydrocarbon in the apparatus with Water and discharging the Water and generated steam together with the residual carbonaceous materials of reaction from the apparatus whereby the various elements of the apparatus are cleared Ofcarbonaceous deposits, then displacing the water in 'the apparatus with a fresh supply of hydrocarbons and repeating the cracking toperation, substantially as described.

, In testimony whereof I hereunto affix my signa-ture.

JOHN C. BLACK. 

